Hung Server Side Script and VSS

This isn't a question so much as an FYI to others who may be experiencing server side scripts that start but never end.

On both FM Server 13 and now FM Server 16, I experienced server scripts that would start but never complete. It seemed like the first script would hang and cause all or most of the subsequent scripts to get stuck in the running state too.

I'm not 100% certain but it seems like the cause of problem was the Microsoft VSS (Volume Snapshot Service) process. It probably started its routine while an FM script was running.

What I don't know about VSS would fill a library but fundamentally VSS is a Microsoft tool that allows a snapshot of a live server to be taken in a matter of seconds. By default our IT group enables VSS across all servers. When FMS started having all of the script hanging problems I asked them to take FMS out of the mix and all has been well since.

Perhaps VSS would be fine if no FM scripts were running when it kicked-off but I'm not going to take that chance.

I would think the better option would be to gracefully shut FM Server down so that no scripts were running and no databases were live and then let VSS do its thing.

I've been trying to track down some issues with other volume "snapshot" tools. AhSayOBM is a program I suspect has caused problems on 2 separate filemaker servers (2012 R2 in both cases) where something went wrong.

Apparently AhSayOBM doesn't allow you to omit folders from the backup process, or at least that was claimed by the IT contact at the company having the issue.

In both instances, we disabled that program entirely, and wrote a scheduled task that copies the filemaker backup folder to a different server so it can be backed up there.

The main thing to remember is that FMS is not VSS aware so it will NOT put the files in a stable state when VSS runs.

That means that when you restore from a snapshot you WiLL get files that are 'improperly closed' at best and 'damaged' as worst.

So don't count on it as a tool in a FM backup strategy. It can still be used to restore the machine itself and the FMS install but not the files. The files would still have to be restored from a real FMS backup.

The procedure can be made safe but it requires coordination with the team that does the VSS. If you use fmsadmin CLI to pause the FMS files and then the VSS runs and then you resume the files using the fmsadmin CLI then the files on the snapshot will be in a good state.

All of this can be done from the CLI, including running the VSS. You don't want to get in a position where the VSS runs on its own schedule and you carefully try to time the FMS pausing/resuming to match that. It is going to be given that the timing will be off at some point and the expectation will still be that you have restorable files.

(Obviously pausing/resuming the files has an impact on the users; they won't get disconnected but their work will be suspended.)